Incubator Age and Incubation Time: Determinants of Firm Survival after Graduation?
Michael Schwartz
IWH Discussion Papers,
No. 14,
2008
Abstract
On the basis of a sample of 149 graduate firms from five German technology oriented business incubators, this article contributes to incubator/incubation literature by investigating the effects of the age of the business incubators and the firms’ incubation time in securing long-term survival of the firms after leaving the incubator facilities. The empirical findings from Cox-proportional hazards regression and parametric accelerated failure time models reveal a statistically negative impact for both variables incubator age and incubation time on post-graduation firm survival. One possible explanation for these results is that, when incubator managers become increasingly involved in various regional development activities (e.g. coaching of regional network initiatives), this may reduce the effectiveness of incubator support and therefore the survival chances of firms.
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Using multivariate statistical methods to identify municipality clusters
Dirk Trocka
Теоретические основы и опыт стратегическ,
2008
Abstract
Eine Volkswirtschaft ist im besonderen Maße auf eine zuverlässige und aktuelle Datenbasis über Vergleiche von Preisen und Preisentwicklungen angewiesen. Die vorliegende Arbeit entwickelt daher eine Methode, um unter Anwendung von multivariaten Verfahren die Repräsentativität der Auswahl der Berichtsgemeinden zur Ermittlung des Verbraucherpreisindex in Sachsen-Anhalt zu verbessern. Dabei werden Variablen zur Anbieter- und Nachfragerstruktur für die Artikel des Warenkorbes des Verbraucherpreisindex berücksichtigt, aber auch Indikatoren der regionalen Bedeutung einer Gemeinde für ihr Umland.
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Metformin-Therapie bei PCO-Syndrom - Positive Vierjahresbilanz des oralen Antidiabetikums
D. Albrecht, P. Kaltwasser, E. Rosenkranz, Dirk Trocka
MedReview,
2007
Abstract
Das Polyzystische Ovarialsyndrom (PCOS) ist mit einer Krankheitshäufigkeit von 4–12 % die häufigste endokrine Erkrankung der Frau im reproduktiven Alter. Neben dem unerfüllten Kinderwunsch stellt es ein hohes Risiko für metabolische (stoffwechselbedingte) und kardiovaskuläre (Herz und Blutgefäße betreffende) Erkrankungen dar. Die Studie stellt die ersten Ergebnisse der Behandlung des PCOS mit dem oralen Antidiabetikum Metformin in einer Vierjahres-Analyse dar und versucht Kriterien für den Einsatz des Arzneistoffes zu definieren.
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Evaluating the German (New Keynesian) Phillips Curve
Rolf Scheufele
IWH Discussion Papers,
No. 10,
2008
Abstract
This paper evaluates the New Keynesian Phillips Curve (NKPC) and its hybrid
variant within a limited information framework for Germany. The main interest rests on the average frequency of price re-optimization of firms. We use the labor income share as the driving variable and consider a source of real rigidity by allowing for a fixed firm-specific capital stock. A GMM estimation strategy is employed as well as an identification robust method that is based upon the Anderson-Rubin statistic. We find out that the German Phillips Curve is purely forward looking. Moreover, our point estimates are consistent with the view that firms re-optimize prices every two to three quarters. While these estimates seem plausible from an economic point of view, the uncertainties around these estimates are very large and also consistent with perfect nominal price rigidity where firms never re-optimize prices. This analysis also offers some explanations why previous results for the German NKPC based on GMM differ considerably. First, standard GMM results are very sensitive to the way how orthogonality conditions are formulated. Additionally, model misspecifications may be left undetected by conventional J tests. Taken together, this analysis points out
the need for identification robust methods to get reliable estimates for the NKPC.
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Determinants of Female Migration – The Case of German NUTS 3 Regions
Alexander Kubis, Lutz Schneider
IWH Discussion Papers,
No. 12,
2007
Abstract
Our study examines the regional patterns and determinants of migration flows of young women. At the NUTS-3 regional level, i.e. the district level (Kreise), the German internal migration flows of the year 2005 are explored. From descriptive statistics it can be seen that peripheral regions in East Germany face the strongest migration deficit with respect to young women, whereas agglomerations in West Germany but also in the East benefit from an intense migration surplus within this group. An econometric analysis of determinants of regional migration flows gives evidence of the importance of labour market, family-related and educational migration motives. Generally speaking, young women tend to choose regions with good income and job opportunities, in addition they seem to be attracted by regions enabling an appropriate balance between family and career. Furthermore the existence of excellent educational facilities is a significant influence for young women’s migration. This educationally motivated type of migration generates a long lasting effect on the regional migration balance, especially when the educational opportunities in the destination region are associated with adequate career perspectives for high qualified female graduates. In view of considerable losses due to migration, the study shows various options for action. An important course of action is to incorporate policy measures improving regional employment and income opportunities. Secondly, extending vocational and academic offers addressed to women seems to be a suitable way to stimulate women’s immigration. Moreover, enhancing the social infrastructure, which contributes to a satisfactory work life balance, might attract young women or at least reduce the number of them leaving a region.
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Can Export Activities of Firms Contribute to the Catching-Up Process of Transitional Economies?
Brigitte Loose, Udo Ludwig
Can the transitional and development economies ever catch up? The Materials from The International Scientific Conference Cracow,
2006
Abstract
In contrast to the majority of the former centrally planned economies, the East German economy has suffered from enormous losses in the transformation process. In the study the question is analyzed whether exports can contribute to the catching-up process in transitional economies. Here it must be explained why the firms emerging out of the privatization process in economies in transition are successful if the export sector consists of small and medium sized enterprises. That is the case with East German manufacturing industry. The study is based on individual company data from the surveys of the East Germany's and North Rhine Westphalia's manufacturing industry between 1995 and 2001 stemming from official statistics.
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Intermediate central communities in Rural Regions - A qualitative instrument for analysis
Alexander Kubis
Теоретические основы и опыт стратегическ,
2006
Abstract
Diese Arbeit untersucht den ländlichen Raum hinsichtlich seiner ökonomischen Potenziale und liefert mittels qualitativer Methoden (Faktoren-, Cluster- und Diskriminanzanalyse) eine verifizierbare Bestimmung spezifische Stärken und Schwächen. Hierbei wurden Gemeindegruppen gesucht und bezüglich ihrer Potenziale eingehend analysiert. Das besondere ist neben der Gemeinde als Untersuchungsebene das Augenmerk auf den Mittelzentren als Bindeglied zwischen Peripherie und Oberzentrum. In den östlichen Bundesländern Deutschlands haben diese Zentren weiterhin einen massiven strukturellen Anpassungsbedarf. Aber auch bei westdeutschen Gemeinden sind spezifische Defizite darstellbar. Die vorgeschlagene Methodik ist innerhalb einer gesamtdeutschen Förderpolitik verallgemeinerbar. Die getroffenen Aussagen haben einen ausreichend statistisch abgesicherten Nachweis.
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Panel Seasonal Unit Root Test: Further Simulation Results and An Application to Unemployment Data
Christian Dreger, Hans-Eggert Reimers
AStA - Advances in Statistical Analysis,
No. 3,
2005
Abstract
In dieser Arbeit wird der saisonale Einheitswurzeltests von Hylleberg et al. (1990) auf heterogene Panel verallgemeinert. Die Prozedur folgt dem Ansatz von Im, Pesaran and Shin (2002) und wird in der Arbeit von Otero et al. (2004) unabhängig von diesem Beitrag vorgeschlagen. Die abgeleiteten Teststatistiken werden dargestellt und kritische Werte mit Hilfe von Simulationen ermittelt. Die Eigenschaften der Tests werden für verschiedene deterministische und dynamische Spezifikationen untersucht. Es zeigt sich, dass für kleine Zeitdimensionen die Güte der Tests auch dann gering ist, wenn die Querschnittsdimension wächst. Bei einer empirischen Analyse erscheint es notwendig, das der Datensatz eine größere Zeitdimension als Querschnittsdimension hat. Das Verfahren wird auf die in Quartalen vorliegenden Arbeitslosenquoten industrialisierter Staaten angewendet. Obwohl in einigen Ländern saisonale Einheitswurzeln gefunden werden, wird die Nullhypothese von saisonalen Einheitswurzeln im Panel abgelehnt. Die Nullhypothese einer Einheitswurzel für die Nullfrequenz wird jedoch im Panel nicht abgelehnt, sodass sich Evidenz für Hysteresiseffekte ergibt.
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Are European Equity Style Indexes Mean Reverting? Testing the Validity of the Efficient Market Hypothesis
Marian Berneburg
IWH Discussion Papers,
No. 193,
2004
Abstract
The article tests for a random walk in European equity style indexes. After briefly
introducing the efficient market hypothesis, equity styles in general and the used
statistical techniques (Variance Ratio Test and modified Rescaled Range Test) it is
shown that a random walk in European equity style indexes cannot be rejected. At least in the period since the mid 70s, for which this research has been conducted, the weak form efficient market hypothesis seems to hold.
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Panel Seasonal Unit Root Test With An Application for Unemployment Data
Christian Dreger, Hans-Eggert Reimers
IWH Discussion Papers,
No. 191,
2004
Abstract
In this paper the seasonal unit root test of Hylleberg et al. (1990) is generalized to cover a heterogenous panel. The procedure follows the work of Im, Pesaran and Shin (2002). Test statistics are proposed and critical values are obtained by simulations. Moreover, the properties of the tests are analyzed for di®erent deterministic and dynamic specications. Evidence is presented that for a small time dimension the power is slow even for increasing cross section dimension. Therefore, it seems necessary to have a higher time dimension than cross section dimension. The new test is applied for unemployment behaviour in
industrialized countries. In some cases seasonal unit roots are detected. However, the null hypotheses of panel seasonal unit roots are rejected. The null hypothesis of a unit root at the zero frequency is not rejected, thereby supporting the presence of hysteresis effects.
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